README
¶
tgo
Go bindings for tidwall/tg Geometry library for C - Fast point-in-polygon
This is partial but functional, tg is a very small self contained C library, tgo compiles tg, no external dependencies needed.
Usage
Simply go get this library with CGO enabled (you'll need a C compiler).
Read from WKT
// Unmarshal from WKT
input := "POLYGON((0 0,0 1,1 1,1 0,0 0))"
g, _ := tgo.UnmarshalWKT(input)
// Marshal to WKT
output := g.AsText()
fmt.Println(output) // Prints: POLYGON((0 0,0 1,1 1,1 0,0 0))
Read from GeoJSON
input := `{"type":"Feature","properties":{},"geometry":{"coordinates":[-79.20159897229003,43.636785010689835],"type":"Point"}}`
g, _ := tgo.UnmarshalGeoJSON(input)
Read from WKB
input := []byte{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 248, 63, 0, 0, 0, 0, 0, 0, 4, 64}
g, _ := tgo.UnmarshalWKB(input)
Intersects
if Intersects(g1, g2) {
fmt.Println("Intersects")
}
Point in Polygon on large FeatureCollections
// load your collection using UnmarshalGeoJSON
found := g.StabOne(2, 48)
if found != nil {
fmt.Println(found.Properties())
}
// Output: {"properties":{ "ADMIN": "France", "ISO_A2": "FR", "ISO_A3": "FRA" }}
Types
input := "POLYGON((0 0,0 1,1 1,1 0,0 0))"
g, _ := tgo.UnmarshalWKT(input)
if g.Types() == tgo.Polygon() {
p, _ := g.AsPoly()
p.HolesCount()
}
Tests
Some tests are borrowed from simplefeatures.
Documentation
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Index ¶
- func Contains(g1, g2 *Geom) bool
- func CoveredBy(g1, g2 *Geom) bool
- func Covers(g1, g2 *Geom) bool
- func Disjoint(g1, g2 *Geom) bool
- func Equals(g1, g2 *Geom) bool
- func Intersects(g1, g2 *Geom) bool
- func Touches(g1, g2 *Geom) bool
- func Within(g1, g2 *Geom) bool
- type Geom
- func UnmarshalGeoJSON(data []byte) (*Geom, error)
- func UnmarshalGeoJSONAndIndex(data []byte, idxt IndexType) (*Geom, error)
- func UnmarshalWKB(data []byte) (*Geom, error)
- func UnmarshalWKBAndIndex(data []byte, idxt IndexType) (*Geom, error)
- func UnmarshalWKT(data string) (*Geom, error)
- func UnmarshalWKTAndIndex(data string, idxt IndexType) (*Geom, error)
- type GeomType
- type IndexType
- type MultiPoly
- type Poly
- type Ring
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Intersects ¶
Types ¶
type Geom ¶
type Geom struct {
// contains filtered or unexported fields
}
func UnmarshalGeoJSON ¶
UnmarshalGeoJSON parses geometries from a GeoJSON representation. Using the Natural indexation.
func UnmarshalGeoJSONAndIndex ¶
UnmarshalGeoJSONAndIndex parses geometries from a GeoJSON representation, and sets the indexation type.
func UnmarshalWKB ¶
UnmarshalWKB parses geometries from a WKB representation. Using the Natural indexation.
func UnmarshalWKBAndIndex ¶
UnmarshalWKBAndIndex parses geometries from a WKB representation, and sets the indexation type.
func UnmarshalWKT ¶
UnmarshalWKT parses geometries from a WKT representation. Using the Natural indexation.
func UnmarshalWKTAndIndex ¶
UnmarshalWKTAndIndex parses geometries from a WKT representation, and sets the indexation type.
func (*Geom) AsMultiPoly ¶
AsMultiPoly returns a MultiPoly of the geometry, returns false if not applicable.
func (*Geom) Properties ¶
Properties returns a string that represents any extra JSON from a parsed GeoJSON geometry. Such as the "id" or "properties" fields.
type GeomType ¶
type GeomType uint8
const ( Point GeomType = iota + 1 // Point. LineString // LineString. Polygon // Polygon. MultiPoint // MultiPoint, collection of points. MultiLineString // MultiLineString, collection of linestrings. MultiPolygon // MultiPolygon, collection of polygons. GeometryCollection // GeometryCollection, collection of geometries. )
type MultiPoly ¶
type MultiPoly struct {
// contains filtered or unexported fields
}
func (*MultiPoly) PolygonsCount ¶
PolygonsCount returns the count of polygons in the multipoly.
type Poly ¶
type Poly struct {
// contains filtered or unexported fields
}
func (*Poly) IsClockWise ¶
IsClockWise returns true if the polygon is clock wise.
Source Files